Arsenal boss Arsene Wenger has claimed they had "no chance" of keeping Alexis Sanchez and suggested the forward is chasing money by joining Manchester United.
The 29-year-old is expected to finalise his move to Old Trafford in the next 48 hours after apparently undergoing a medical on Sunday, with Henrikh Mkhitaryan heading to the Gunners in a straight swap deal.
Reports in England have said Sanchez could earn as much as £450,000 a week at United as part of a salary package that even Manchester City refused to match, despite their long-standing interest in the player.
Wenger says he "cannot understand" the decision of a player to leave the Emirates Stadium but believes the money on offer ultimately proved too tempting for the Chile international, who was in the last six months of his Gunners deal.
"I cannot understand anybody wanting to leave Arsenal. But, in 30 years of doing transfers, you learn a lot about human beings," Wenger said.
"As a professional, it was perhaps his last contract at the top level and an important contract. After that, I accept that because we accepted that we would let him go. After that, we analyse the pros and the cons.
"We did what we tried to do and went as far as we could. Even Manchester City moved out of it in the end. That tells you we had no chance to give him a contract.
"We have tried to find the best possible solution and the best possible solution is that we lose a world class player – I don't deny that at all – but we did not lose him without getting somebody after. The future will tell if it was the right decision or not.
"It is not that we are only losing a player, we are gaining a player as well. And we are still active in the transfer market and trying to bring players in."
Wenger also admitted the uncertainty over Sanchez's future has taken its toll on the rest of the squad this season.
"There are periods when the atmosphere is less enjoyable than others," he said. "It is the lack of clarity. It is not losing players – teams are used to losing players. But it is the fact that you have uncertainty in the group – that they don’t know if he will be here or not.
"Once it is clear, the team gets used to it."
With Mkhitaryan arriving and a pursuit of Borussia Dortmund striker Pierre-Emerick Aubameyang in progress, Arsenal could end the transfer window in a strong position despite the loss of Sanchez.
Questions have been raised about how Aubameyang will fit into the side alongside record signing Alexandre Lacazette, but Wenger appears to have no such concerns.
"How do I fit them in? I just play the good players. They can always play together," he said.